The smallest price change that a given exchange rate can make. Since most major currency pairs are priced to four decimal places, the smallest change is that of the last decimal point - for most pairs this is the equivalent of 1/100 of one percent, or one basis point.
Investopedia Says: For example, the smallest move the USD/CAD currency pair can make is $0.0001, or one basis point. The smallest move in a currency does not always need to be equal to one basis point, but this is generally the case with most currency pairs.
Spread vs commission?
